High-frequency generating- system



D. G. McCAA.

-H|GH FREQUENCY GENERATING SYSTEM.

APPLICATION FILED MAY 26. I917.

Patented Nov. 23,1920. 7

15 IIIIIIII II! III DAVID e. McoAA, or LANCASTER, PENNSYLVANIA.

HIGH-FREQUENCY GENERATING SYSTEM.

Specification of Letters Patent. Patgnted Nov 23, 192() Application filed May 26, 1917. Serial No. 171,179.

To all whom it may] concern Be it known that I, DAVID G. MoCAA, a citizen of the United States, residing in the city and county of Lancaster, State of Pennsylvania, have invented High-Frequency Generating Systems, of which the following is a specification.

This invention relates to apparatus for the production of sustained or continuous oscillatory currents of high frequency, such as are used in the art of signaling by electromagnetic waves.

One object of the invention is to provide a simple, durable and easily operated combination or system of apparatus whereby it shall be possible to convert a single phase alternating current, such as that supplied from commercial lighting main-s, into continuous high frequency oscillations of uniform power, for use in radio telegraphy and telephony.

It is further desired to provide a system of the general type above noted which shall be positive and relatively stable inaction, of such a nature as shall not require adjustment when in action. and from which it shall be possible to obtain currents having a wide range of frequencies.

These objects and other advantageous ends I secure as hereinafter set forth, reference being had to the accompanying drawings, in which,

Figure 1 is a diagrammatic View illustrating a system of apparatus for producing sustained oscillations in a radiating circuit and in which thevarious parts are arranged and connected in accordance with 'myinvention; and

Fig. 2 is a diagrammatic view illustrat' ing the phase relations of the low frequency currents in certain parts of the system and also illustrating the type of primary and secondary high frequency oscillations as well as their relation, as regards power, to said low frequency current.

In Fig. 1 of the above drawings, 1 represents a source of alternating current such as an alternator of any definite frequency ranging for example, from twenty-five to'two thousand cycles, or it maybe the mains of a commercialrlighting system in which a sixty cycle current is supplied at a pressure of one hundred and fifteenvolts.

Connected to this source in parallel with each other are two circuts A and B, and of these the first includes a device 2.for male ing and breaking the current flow in said circuit, a condenser 3 and the primary windwinding 14 of a second high frequency transformer, and a ground connection 15.

The second inain circuit B includes a device 16 for making and breaking'the current How, a reactance coil*17 and" the primary winding 18 of a transformer 19. The

secondary winding 20 of this transformer is connected in circuit with a second reactance coil 21 and with a condenser 22, while the V latter has in shunt toit a quenched spark 23 and the primary winding 2-1 of the second high frequency transformer, whose secondary is connected in the antenna circuit 12.

The circuits 8910 and 22-'23-2 1, are

preferably designed to have equal capacities 8 and 22, equal inductances 10 and24r, and

the same gap conditions, although this uniformity is not absolutely essential to the suc cessful operation of my invention and I do not limit myself to such construction. These two circuits constitute the primary high frequency oscillatory systems which supply the secondary or antenna systems 1311-'1 1 15 and maintain it in continuous oscillation under operating conditiens. The function of the remainder of the apparatus is to supply to the condensers 8 and 22, low frequency hightension currents which are of equal power and which are properly controlled as to the amount of power and properly spaced as regards their time relation. In an oscillatory circuit such as that pro vided by the elements 89-10 or 2223 24, it is possible, by properly adjusting the capacity, the length and number ofthe spark gaps, and the supply current, to obtain highly damped discharges at exceedingly high group frequencies. The damping is independent of any reaction by a secondary circuit and the action of the dis charges in the secondary circuit assumes a type of impulse excitation. Group frequencies of from twenty to forty thousand impulses a second are obtainable and as the primary discharges occur throughout the ma or portion of each alternatlon oftheaccomplished by the introduction of capacity, resistance, or inductance, in either the primary orsecondary, or in both the primary and the secondary circuits, of the supplying transformer. In this case, capacity operates as a capacity reactancc determinable by the formula 2 in Which'N is the frequency and J is the capacity. Iu ductance operates as magnetic reactance and is determined by the formula QWNL. Both the capacity and inductance operate in a -manner similar to resistance and limit the current flow.

The-condensers 3 and 7 in the circuit A and the reactance coils 17 and 21. of the circuit B are so designed relatively to the transformer windings i and (5 on the one hand and to the windings 18 and20 on the other, as to permit the same currents to flow to charge the condensers 8 and 22. lVith the arrangement of circuits shown in Fig. l,

the current flowing to and charging the con-' denser 8 will be out of phase with the currentflowing to and charging the condenser 22 as would not be the case 1f resistance was employed-to control or limit the current flow to said condensers, for the capacity provided in circuit A by the condensers 3 and '7, causes the current in this circuit to lead the impressed electro-inotive torce. while the inductance provided by the coils l7 and 21in circuit 13. causes the current in the latterto lagbehind the impressed electromot-ive force- In both circuits the inductance of the primary and secondary windings of; the transformers 5 and 19, is balanced against the capacity of the condensers 8* and 22.

In order to obtain the prooer time relation between the currents supplied to the con" I and are 90 apart, are at right an The curved line 27 similarly represents the 7 current leadin the impressed elcctro-inotive force by an an 'le of er ;the distance from the vertical line 28 to the iarallel line M being equal to one-fourth of one alternation. The curved line .30 represents the current laggingfbehind the impressed electro-inotive force by an angle of e5 the distance from the line 29 to the line 81 being equal to one-- fourth of one alternation. ()bviouslythercfore the currents represented by the lines gles or in quadrature to each other and therefore in quarter or two phase relation.

lVhile the impressed electro motive force of the source and the current supplied are usually not in phase, this condition will not interfere with the operation of the system, since suitably selected capacities and reactances may be employed to advance or retard the current as required, until the desired 90 phase difference is obtained. As will be understood by those skilled in the art. it is not necessary that the current in one circuit shall be advanced -15 and the other retarded the remaining as indicated in Fig.

2. since any angle of lead and any angle of lag may be employed provided the sum of the two angles equals 90;

Since the leading effect of capacity and the lag effect of inductance are decreased by resistance, it is preferable to keep the ohmic resistance of the circuits relatively low.

As indicated in Fig; 2, the condenser will dischargeas described during the time period of the alternations of its supply current, the highly damped primary discl'iarges induced by the current indicated by the line 27 being represented at 82 and their power vby the varying ordinates of said line. Simicontinuous owing-to the overlapping of the power supplied to the two circuits. The

line 34: therefore represents the secondary.

or antenna oscillations and its ordinates are all equal, by reason of the quarter phase relation and of the above described adjustment of the current flowin the primary oscillatory systems 891O and 22239A-.

I claim 1. A generator for continuous high frequency oscillations comprising a source of single phase alternating current; two circuits connected thereto and each including a primary high frequency oscillatory quenched gap system; a secondary high frequency oscillatory system coupled to both of said primary systems; and means for causing a phase difference of 90 in the currents of said primary systems.

2. The combination of an antenna system; two high frequency oscillatory systems coupled to said antenna system; and means for maintaining continuous high frequency oscillations in the antenna system including means for supplying to said oscillatory sys tems low frequency high tension currents having a phase difference of 90.

3. The combination of a source of single phase current; two low frequency high tension circuits supplied therefrom; means for causing the current in one circuit to lead the impressed electro-motive force; means for causing the current in the other circuit to lag behind the impressed electro-motivc force; primary high frequency oscillatory systems actuated from said low frequency systems and comprising a quenched spark gap; and a secondary high frequency oscillatory system coupled to both of said primary high frequency systems.

4. A generator for continuous high frequency oscillations comprising a source of single phase current; two low frequency high tension systems operatively connected to said current source and including means whereby the currents flowing in them are caused to have a phase difference of 90; primary high frequency oscillatory systems operatively associated with said low frequency systems and including quenched spark gaps; and a secondary high frequency oscillatory system coupled to both of said primary systems.

5. A generator for continuous high fre quency oscillations comprisng a source of single phase current; two low frequency high tension systems supplied therefrom; a capacity for causing a leading current in one of said systems; a reactance for causing a lagging current in the other system; primary high frequency oscillatory systems respectively associated with said low frequency systems and including quenched spark gaps; and a secondary high. frequency oscillatory system operatively associated with said primary systems.

6. A generator for continuous high frequency oscillations comprising a source of single phase'alternating current; two circuits connected in parallel to said source; a

condenser in one of said circuits; a reactance 1n the other circuit; two transformers having their primary windings respectively connected in said circuits; condensers connected in circuit with the secondary windings of the transformers respectively; a quenched spark gap and the primary winding of a high frequency transformer in circuit with each of said latter condensers; and an antenna circuit including two secondary high frequency transformer windings respectively associated with said high frequency primary windings.

7. The combination of a source of alternating current; two circuits connected in paral lel therewith; two transformers having their primary windings respectively connected in said two circuits; two condensers in circuit with the secondary winding of one of said transformers; a condenser and a reactance in circuit with the secondary winding of the other transformer; two high frequency transformers; spark gaps respectively connected in circuit with the primary windings of said high. frequency transformers and with one of the condensers of said circuits; and an antenna connected in circuit with the two secondary windings of said high frequency transformers.

8. The combination of a source of alternating current; two primary high frequency oscillatory systems connected in parallel to said source; a secondary high frequency oscillatory system coupled to both of said primary systems; and means for controlling the amounts of power supplied to the primary oscillatory systems, consisting of capacity in one of said primary systems and inductance in the other primary system.

9. A generator for continuous high frequency oscillations comprising a source of single phase alternating current; two primary high frequency oscillatory systems co nnected'in parallel to said source and including quenched spark gaps; a secondary, high frequency oscillatory system coupled to both of said primary systems; and means for controlling the amounts of power supplied to the primary oscillatory systems, said apparatus being adjusted to maintain a phase difference of 90 between the currents in the ling said latter systems consisting of capacity reactance in one of them and magnetic reactance in the other. s

11. The combination of a source of alternating current; two primary high frequency oscillatory systemsconnected to said source in parallel with each other; an antenna systern operatively coupled to both of said oscillatory systems; with means for controlling said latter systems consisting of capac- 10 ity reactan'ce in one of them and magnetic reactance in the other said primary oscillatory systems being adjusted to cause a phase difference of 90 between the currents flowing therein. 15

In witness whereof I affix my signature.

DAVID G. MGOAA. 

